New soluble polyamides and polyimides containing polar functional groups: pendent pyrazole rings with amino and cyano groups

Abstract

A series of aromatic polyamides and polyimides containing pendent pyrazole rings with amino and cyano groups were prepared from a new monomer, 1-(2,4-diaminophenyl)-3-phenyl-4-cyano-5-aminopyrazole, which was prepared from (chloromethylene)propanedinitrile and 2,4-dinitrophenyl hydrazine with two steps. In addition, model compounds were synthesized and characterized by elemental analyses, Fourier transform infrared (FTIR), and nuclear magnetic resonance (NMR) spectroscopy. The amino and cyano groups on the pyrazole ring were not affected during the polymerization process. The synthesized polymers, with intrinsic viscosities of 0.33-0.53 dL/g, were soluble in various organic solvents. They showed no T g values before degradation, and the 5% weight loss temperature of the polyamides and the polyimides occurred at approximately 420 and 470 °C, respectively. They also underwent no thermal transitions, such as degradation or crosslinking, up to 440 °C in spite of the presence of pendent amino and cyano groups.

Synergistic effect of polyfunctional silane coupling agent and styrene acrylonitrile copolymer on the water‐resistant and mechanical performances of glass fiber–reinforced polyamide 6

“…Figure C displays the FTIR results of SAN and PFS and their blend. The peak of the telescopic vibration for the cyano group (–CN) in SAN was observed at 2237 cm −1 and the vibrations of amidogen (–NH 2 ) and the imino group (–NH–) in PFS at 2937 and 2839 cm −1 , respectively . A new peak of telescopic vibration for the carbon‐nitrogen double bond (C═N) appeared in the spectrum of the SAN/PFS blend at 1640 cm −1 , and the apparent decline of the relative intensity of the –CN group was observed compared with that of pristine SAN, which can be attributed to the chemical reaction between SAN and PFS.…”

Synthesis and Properties of Fluorinated Polyimides from Rigid and Twisted Bis(Trifluoromethyl)Benzidine for Flexible Electronics

“…To overcome these problems, much research effort has focused on the synthesis of soluble and transparent PIs in a fully imidized form without deterioration of their excellent properties [4,6]. Several successful approaches to synthesize soluble and transparent PIs, including the insertion of flexible or unsymmetrical linkages or bulky substituents on the main chain and the use of noncoplanar or alicyclic monomers, have been introduced over the last few decades [4][5][6][7][8].…”